cli: show timestamp of the block

.gitignore

@@ -1,2 +1,5 @@
 *.db
 *.dat
+cscope.*
+.*.swp
+blockchain_go

README.md

@@ -9,3 +9,29 @@ A blockchain implementation in Go, as described in these articles:
 5. [Addresses](https://jeiwan.cc/posts/building-blockchain-in-go-part-5/)
 6. [Transactions 2](https://jeiwan.cc/posts/building-blockchain-in-go-part-6/)
 7. [Network](https://jeiwan.cc/posts/building-blockchain-in-go-part-7/)
+
+# Quick Start
+
+## Download and install
+
+    go get github.com/richardweiyang/blockchain_go
+
+## Create file `main.go`
+
+source code
+
+```go
+package main
+
+import "github.com/richardweiyang/blockchain_go"
+
+func main() {
+	cli := bc.CLI{}
+	cli.Run()
+}
+```
+#### Build and run
+
+    go build main.go
+    ./main
+

base58.go

@@ -1,4 +1,4 @@
-package main
+package bc
 
 import (
 	"bytes"
@@ -40,8 +40,10 @@ func Base58Decode(input []byte) []byte {
 	zeroBytes := 0
 
 	for _, b := range input {
-		if b == 0x00 {
+		if b == b58Alphabet[0] {
 			zeroBytes++
+		} else {
+			break
 		}
 	}
 

base58_test.go

@@ -0,0 +1,27 @@
+package bc
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBase58(t *testing.T) {
+	for i := 0; i < 100; i++ {
+		_, public := newKeyPair()
+		pubKeyHash := HashPubKey(public)
+
+		versionedPayload := append([]byte{version}, pubKeyHash...)
+		checksum := checksum(versionedPayload)
+
+		fullPayload := append(versionedPayload, checksum...)
+		address := Base58Encode(fullPayload)
+
+		assert.Equal(
+			t,
+			ValidateAddress(string(address[:])),
+			true,
+			"Address: %s is invalid", address,
+		)
+	}
+}

block.go

@@ -1,9 +1,12 @@
-package main
+package bc
 
 import (
 	"bytes"
 	"encoding/gob"
+	"fmt"
 	"log"
+	"strconv"
+	"strings"
 	"time"
 )
 
@@ -71,3 +74,20 @@ func DeserializeBlock(d []byte) *Block {
 
 	return &block
 }
+
+func (b *Block) PrintHTML(detail bool) string {
+	var lines []string
+	lines = append(lines, fmt.Sprintf("<h2>Block <a href=\"/block/%x\">%x</a> </h2>", b.Hash, b.Hash))
+	lines = append(lines, fmt.Sprintf("Height: %d</br>", b.Height))
+	lines = append(lines, fmt.Sprintf("Prev. block: <a href=\"/block/%x\">%x</a></br>", b.PrevBlockHash, b.PrevBlockHash))
+	lines = append(lines, fmt.Sprintf("Created at : %s</br>", time.Unix(b.Timestamp, 0)))
+	pow := NewProofOfWork(b)
+	lines = append(lines, fmt.Sprintf("PoW: %s</br></br>", strconv.FormatBool(pow.Validate())))
+	if detail {
+		for _, tx := range b.Transactions {
+			lines = append(lines, tx.PrintHTML())
+		}
+	}
+	lines = append(lines, fmt.Sprintf("</br></br>"))
+	return strings.Join(lines, "\n")
+}

blockchain.go

@@ -1,4 +1,4 @@
-package main
+package bc
 
 import (
 	"bytes"
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"strings"
 
 	"github.com/boltdb/bolt"
 )
@@ -19,7 +20,7 @@ const genesisCoinbaseData = "The Times 03/Jan/2009 Chancellor on brink of second
 // Blockchain implements interactions with a DB
 type Blockchain struct {
 	tip []byte
-	db  *bolt.DB
+	DB  *bolt.DB
 }
 
 // CreateBlockchain creates a new blockchain DB
@@ -82,7 +83,7 @@ func NewBlockchain(nodeID string) *Blockchain {
 		log.Panic(err)
 	}
 
-	err = db.Update(func(tx *bolt.Tx) error {
+	err = db.View(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(blocksBucket))
 		tip = b.Get([]byte("l"))
 
@@ -99,7 +100,7 @@ func NewBlockchain(nodeID string) *Blockchain {
 
 // AddBlock saves the block into the blockchain
 func (bc *Blockchain) AddBlock(block *Block) {
-	err := bc.db.Update(func(tx *bolt.Tx) error {
+	err := bc.DB.Update(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(blocksBucket))
 		blockInDb := b.Get(block.Hash)
 
@@ -199,7 +200,7 @@ func (bc *Blockchain) FindUTXO() map[string]TXOutputs {
 
 // Iterator returns a BlockchainIterat
 func (bc *Blockchain) Iterator() *BlockchainIterator {
-	bci := &BlockchainIterator{bc.tip, bc.db}
+	bci := &BlockchainIterator{bc.tip, bc.DB}
 
 	return bci
 }
@@ -208,7 +209,7 @@ func (bc *Blockchain) Iterator() *BlockchainIterator {
 func (bc *Blockchain) GetBestHeight() int {
 	var lastBlock Block
 
-	err := bc.db.View(func(tx *bolt.Tx) error {
+	err := bc.DB.View(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(blocksBucket))
 		lastHash := b.Get([]byte("l"))
 		blockData := b.Get(lastHash)
@@ -227,7 +228,7 @@ func (bc *Blockchain) GetBestHeight() int {
 func (bc *Blockchain) GetBlock(blockHash []byte) (Block, error) {
 	var block Block
 
-	err := bc.db.View(func(tx *bolt.Tx) error {
+	err := bc.DB.View(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(blocksBucket))
 
 		blockData := b.Get(blockHash)
@@ -277,7 +278,7 @@ func (bc *Blockchain) MineBlock(transactions []*Transaction) *Block {
 		}
 	}
 
-	err := bc.db.View(func(tx *bolt.Tx) error {
+	err := bc.DB.View(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(blocksBucket))
 		lastHash = b.Get([]byte("l"))
 
@@ -294,7 +295,7 @@ func (bc *Blockchain) MineBlock(transactions []*Transaction) *Block {
 
 	newBlock := NewBlock(transactions, lastHash, lastHeight+1)
 
-	err = bc.db.Update(func(tx *bolt.Tx) error {
+	err = bc.DB.Update(func(tx *bolt.Tx) error {
 		b := tx.Bucket([]byte(blocksBucket))
 		err := b.Put(newBlock.Hash, newBlock.Serialize())
 		if err != nil {
@@ -358,3 +359,33 @@ func dbExists(dbFile string) bool {
 
 	return true
 }
+
+func (bc *Blockchain) PrintHTML() string {
+	var lines []string
+	bci := bc.Iterator()
+
+	for {
+		block := bci.Next()
+
+		lines = append(lines, block.PrintHTML(false))
+
+		if len(block.PrevBlockHash) == 0 {
+			break
+		}
+	}
+	return strings.Join(lines, "\n")
+
+}
+
+func (bc *Blockchain) GetBalance(address string) int {
+	UTXOSet := UTXOSet{bc}
+	balance := 0
+	pubKeyHash := Base58Decode([]byte(address))
+	pubKeyHash = pubKeyHash[1 : len(pubKeyHash)-4]
+	UTXOs := UTXOSet.FindUTXO(pubKeyHash)
+
+	for _, out := range UTXOs {
+		balance += out.Value
+	}
+	return balance
+}

blockchain_iterator.go

@@ -1,4 +1,4 @@
-package main
+package bc
 
 import (
 	"log"

cli.go

@@ -1,4 +1,4 @@
-package main
+package bc
 
 import (
 	"flag"
@@ -21,6 +21,14 @@ func (cli *CLI) printUsage() {
 	fmt.Println("  reindexutxo - Rebuilds the UTXO set")
 	fmt.Println("  send -from FROM -to TO -amount AMOUNT -mine - Send AMOUNT of coins from FROM address to TO. Mine on the same node, when -mine is set.")
 	fmt.Println("  startnode -miner ADDRESS - Start a node with ID specified in NODE_ID env. var. -miner enables mining")
+	fmt.Println()
+	fmt.Println("Exploring cmds:")
+	fmt.Println("  generatePrivKey - generate KeyPair for exploring")
+	fmt.Println("  getPubKey -privKey PRIKEY - generate PubKey from privateKey")
+	fmt.Println("  getAddress -pubKey PUBKEY - convert pubKey to address")
+	fmt.Println("  getPubKeyHash -address Address - get pubKeyHash of an address")
+	fmt.Println("  validateAddress -addr Address - validate an address")
+	fmt.Println("  getBlock -hash BlockHash - get a block with BlockHash")
 }
 
 func (cli *CLI) validateArgs() {
@@ -48,6 +56,12 @@ func (cli *CLI) Run() {
 	reindexUTXOCmd := flag.NewFlagSet("reindexutxo", flag.ExitOnError)
 	sendCmd := flag.NewFlagSet("send", flag.ExitOnError)
 	startNodeCmd := flag.NewFlagSet("startnode", flag.ExitOnError)
+	generatePrivKeyCmd := flag.NewFlagSet("generatePrivKey", flag.ExitOnError)
+	getPubKeyCmd := flag.NewFlagSet("getPubKey", flag.ExitOnError)
+	getAddressCmd := flag.NewFlagSet("getAddress", flag.ExitOnError)
+	getPubKeyHashCmd := flag.NewFlagSet("getPubKeyHash", flag.ExitOnError)
+	validateAddrCmd := flag.NewFlagSet("validateAddress", flag.ExitOnError)
+	getBlockCmd := flag.NewFlagSet("getBlock", flag.ExitOnError)
 
 	getBalanceAddress := getBalanceCmd.String("address", "", "The address to get balance for")
 	createBlockchainAddress := createBlockchainCmd.String("address", "", "The address to send genesis block reward to")
@@ -56,6 +70,11 @@ func (cli *CLI) Run() {
 	sendAmount := sendCmd.Int("amount", 0, "Amount to send")
 	sendMine := sendCmd.Bool("mine", false, "Mine immediately on the same node")
 	startNodeMiner := startNodeCmd.String("miner", "", "Enable mining mode and send reward to ADDRESS")
+	privateKey := getPubKeyCmd.String("privKey", "", "generate PubKey based on this")
+	pubKey := getAddressCmd.String("pubKey", "", "the key where address generated")
+	pubKeyAddress := getPubKeyHashCmd.String("address", "", "the pub address")
+	address := validateAddrCmd.String("addr", "", "the public address")
+	blockHash := getBlockCmd.String("hash", "", "the block hash")
 
 	switch os.Args[1] {
 	case "getbalance":
@@ -98,6 +117,36 @@ func (cli *CLI) Run() {
 		if err != nil {
 			log.Panic(err)
 		}
+	case "validateAddress":
+		err := validateAddrCmd.Parse(os.Args[2:])
+		if err != nil {
+			log.Panic(err)
+		}
+	case "generatePrivKey":
+		err := generatePrivKeyCmd.Parse(os.Args[2:])
+		if err != nil {
+			log.Panic(err)
+		}
+	case "getPubKey":
+		err := getPubKeyCmd.Parse(os.Args[2:])
+		if err != nil {
+			log.Panic(err)
+		}
+	case "getPubKeyHash":
+		err := getPubKeyHashCmd.Parse(os.Args[2:])
+		if err != nil {
+			log.Panic(err)
+		}
+	case "getAddress":
+		err := getAddressCmd.Parse(os.Args[2:])
+		if err != nil {
+			log.Panic(err)
+		}
+	case "getBlock":
+		err := getBlockCmd.Parse(os.Args[2:])
+		if err != nil {
+			log.Panic(err)
+		}
 	default:
 		cli.printUsage()
 		os.Exit(1)
@@ -152,4 +201,53 @@ func (cli *CLI) Run() {
 		}
 		cli.startNode(nodeID, *startNodeMiner)
 	}
+
+	if generatePrivKeyCmd.Parsed() {
+		cli.generatePrivKey()
+	}
+
+	if getPubKeyCmd.Parsed() {
+		if *privateKey == "" {
+			getPubKeyCmd.Usage()
+			os.Exit(1)
+		}
+		cli.getPubKey(*privateKey)
+	}
+
+	if getAddressCmd.Parsed() {
+		if *pubKey == "" {
+			getAddressCmd.Usage()
+			os.Exit(1)
+		}
+
+		cli.getAddress(*pubKey)
+	}
+
+	if getPubKeyHashCmd.Parsed() {
+		if *pubKeyAddress == "" {
+			getPubKeyHashCmd.Usage()
+			os.Exit(1)
+		}
+
+		cli.getPubKeyHash(*pubKeyAddress)
+	}
+
+	if validateAddrCmd.Parsed() {
+		if *address == "" {
+			validateAddrCmd.Usage()
+			os.Exit(1)
+		}
+
+		cli.validateAddr(*address)
+	}
+
+	if getBlockCmd.Parsed() {
+		if *blockHash == "" {
+			getBlockCmd.Usage()
+			os.Exit(1)
+		}
+
+		cli.printBlock(*blockHash, nodeID)
+	}
+
 }

cli_createblockchain.go

@@ -1,4 +1,4 @@
-package main
+package bc
 
 import (
 	"fmt"
@@ -10,7 +10,7 @@ func (cli *CLI) createBlockchain(address, nodeID string) {
 		log.Panic("ERROR: Address is not valid")
 	}
 	bc := CreateBlockchain(address, nodeID)
-	defer bc.db.Close()
+	defer bc.DB.Close()
 
 	UTXOSet := UTXOSet{bc}
 	UTXOSet.Reindex()